Inlet-opening or eye of centrifugal fans or pumps.



PATENTED MAY 15, 1906.

S. C. DAVIDSON. INLET OPENING OR EYE OF CENTRIFUGAL FANS 0R PUMPS.

APPLICATION FILED JAN.Z7,1905.

4 SHEETS-SHEET 1v W/T/VESSES:

PATENTED Min 15, 1906.

v S. G. DAVIDSON. INLET OPENING OR EYE OF OENTRIFUGAL FANS ORPUMPS.

APPLICATION FILED JAN. 27. 1905.

4 SHEETS-SHEET 2 W/T/VESSES:

PATENTED MAY 15, 1906 v s. 0. DAVIDSON. INLET OPENING OR EYE OF OENTRIPUGAL FANS OR PUMPS.

APPLICATION FILED JAN. 27. 1905.

4 SHEETSSHEET 3 No. 820,399. PATENTED MAY 15, 1906. S G. DAVIDSON. INLET OPENING 0R EYE OF GENTRII'UGAL FANS OR PUMPS.

APPLICATION FILED JAN 27. 1905.

4 SHEETSr-SHEET 4 FIG. 7.

d INVENTOR:

WITNEDSES: fwm By AZZOIIUWS,

, UNITED STATES:

PATENT orrron.

INLET-OPENING OH EYE OF CENTRIFUGAL FANS OR PUMPS.

Specification of Letters Patent.

Patented may 15, 1906.

Application filed January 27, 1905. serial No. 242,971.

To all whom it may concern:

Be it known that I, SAMUEL OLELAND DA- VIDSON, a subject of the King of Great Britain and Ireland, and a resident of Sirocco Engineering Works, Belfast, Ireland, have invented certain new and useful Improvements in and Relating to the Inlet-Opening or Eye of Centrifugal Fans or Pumps, of which the followin is a specification.

This invention re ates to the inlet-opening or e e of centrifugal fans or pumps.

T e invention is particularly applicable to centrifugal fans or pumps of the type illustrated in Patent No. 662,395, granted to me on November 27, 1900, which relates to a fan-wheel having numerous elongated blades arranged in drum form, so as to inclo se within them a relatively large and substantially unobstructed intake-chamber. Ina pending application, Serial No. 229, 896, filed October 25, 1904, I have illustrated certain improvements which are es ecially applicable to this type of fan, the preferred construction therein shown comprising a fan-wheel having blades which are shorter than the depth of the casing and an eye formed with an inwardly-extenged throat disposed eccentrically to the fa -wheel shaft. The present invention relates to an improved construction of such e e and throat, and while especially adapted fidr use with fans of the construction above referred to is applicable to various other types of centrifugal fans.

According to this invention I employ an eye or inlet-opening with a throat extended within the-fan-casing. The inward termination of said throat, which may be circular or non-circular, (but preferably circular,) is eccentric to the axis of the fans rotation, and the entrance to said throat is of larger dimensions than the inner termination and of suitable form and situation. For instance, it may be either'concentric or eccentric with the axis of the fan or concentric with or more or less eccentric to the inward termination of the throat of the eye.

I will now describe some forms of my invention as a plied to a fan-wheel and easing of the type escr'ibed in my said pending application, Serial No. 229,896, wherein the fan-wheel blades are axially shorter than the width of the casing.

Figure 1 is an elevation, and Fig. 2 is a section of Fig. 1 on the line X Y. Figs. 3 and 4 are similar views to Figs. 1 and 2, showing a modification. F i s. 5 and 6 are similar views of another mo ification; and Figs. 7, 8, and 9 show further modifications.

Referring to Figs. 1 and 2 as applied to the type of fans referred to, the inner terminat1on or inner end of the throat of the eye a, is of circular formation and eccentric to and of smaller diameter than the circle I) described by the inner ed es of the fan-blades c and is extended inwar more or less up toor beyond the lane of the intake ends of the fan-wheel bla es 0. In the drawings the end a of the eye is shown as extended not quite up to the p ane of the fan-Wheel blade'ends, and it is obvious that if it is extended inward beyond the said plane the bounda a of the e e must not extend beyond t e circle I) escribed by the inner edges thereof. The eccentric displacement of the inner termination a of the eye is such as to bring it closest to the circumference of the fan-wheel where the suction thereof is strongest-i. e., in the fan shown in the drawings the displacement will be toward the' right-hand side of the figure, as shown, so as to bring one side of the inner termination a coincident with the blades 0 within or sometimes even without the circle I) described by the inner edges thereof. In centrifugal fans inclosed in a snail-shaped casing the position of greatest suction will generally be on the opposite side of the fanwheel to that part whlch comes closest to the outer circumference of the casing. The position will, however, be determined by the particular type of fan and casing to which the invention is applied.

The position of the inner termination a of the throat of the eye, as just described, is eccentric to the axis of the fan. The entrance d of the threat is, however, of larger dimensions than the inner termination a and is referabl concentric to the circle I) of the an-whee blades or the axis of the fan-wheel, in which case the entrance (1 will coincide more or less with one side of the inner termination of the eye, whereby the wall of the throat at the side e will be substantially at right angles to the plane of revolution of the fan-wheel f and inclined on. the other side 9', according to the relative dimensions of the entrance (1 and the inner termination a of the eye. If the larger entrance is concentric with the smaller inner termination, the wall of the throat will of course form a truncated cone, as shown in Figs..3 and 4, where simirro lar letters of reference are used to Figs. 1 and 2, with the exception of that referring to the wall the throat, which in this case is indicated y the letter h.

In another form shown in Figs. 5 and 6 the entrance d to the throat may be both eccentric to the inner termination a and eccentric to the circle of the fan-blades c, and as will be a parent from these figures the walls of the tfiroat will be of greater angle on the one side g than on the other side e. The inner termination a of the eye may in some cases be of irregular formation extending inward more on one side than on the other. For instance, in a fan of the type referred to, and as shown in Fig. 6, the wall g which is nearest-the axis of the fan-wheel may be extended, as at i, be-

ond the plane of the intake ends of the blades, and such extension may be either parallel with the axis of the fan-wheel f, as shown in this figure, or it may be in aline- 7 ment with the angular wall g, as shown at t in Fig. 7, which otherwise corres ends with Fig. 2. The extension 11 may lie of equal depth, or it may gradually fade away, as shown in the drawin s, toward the adj oining parts or opposite wal c, Fig. 7. The angles and corners may be rounded off by suitable curves. Extensions such as referred to may also be employed with the form of throat shown in Figs. 3 and 4:, Figs. 8 and 9 illustrating such constructions.

What I claim as my invention, and desire to secure by Letters Patent, is-

i. In a centrifugal fan or pump, a fanwheel, and an eye leading thereto constructed in the form of a throat, the inner termination thereof being eccentric to the axis of the fanwheel.

2. In a centrifugal fan or pump, a fanwheel, and an eye leadin thereto constructed in'the form of a throat, t e inner termination thereof being eccentric to the axis of the fan wheel, and the entrance thereof being concentric with such axis.

3. In a centrifugal fan or pump, a fanwheel, and an eye leading thereto constructed in the form of a throat the inner termination of said throat being smaller than the entrance thereto, and being eccentric to the axis of the fan-wheel.

4. In a centrifugal fan -or pump, a fanwheel, and an eye leadin thereto constructed in the form of a throat, the inner termination of said throat bring smaller than the entrance thereto, and being eccentric to the axis of the fan-wheel, and the entrance thereof being con centric with such axis.

5. In a centrifugal fan or pump, a fanwheel, and aneye leading thereto constructed in the formv of a throat, the inner termination thereof being eccentric to the entrance thereof.

6. In a centrifugal fan or pump, a fanwheel, and'an eye leading thereto constructed in the form of a throat, the inner termination thereof being smaller than its entrance, and being eccentric thereto.

7. In a centrifugal fan or pump, a fan Wheel, and an eye leadin thereto constructed in the form of a throat, t e inner termination thereof being smaller than its entrance, and being eccentric thereto, and said entrance being concentric with the fan-Wheel axis.

8. In a centrifugal fan or pump, a fan- Wheel, and an eye leadin thereto constructed in the form of a throat, t e inner termination thereof being smaller than the circle described by the fan-blades, and eccentric thereto, and the entrance thereof being larger than the said inner termination an concentric with such circle.

9. In a centrifugal fan or pump, a snail shaped casing, a fan wheel mounted to rotate therein, and an eye constructed in the form of a throat leading from said casing to said fan-wheel, said throat having its inner termination smaller than its entrance and eccentric to the axis of the fan-wheel.

10. In a centrifugal fan or pump, a snailshaped. casing, a fan-wheel mounted to rotate therein, and an eye constructed in the form of a throat leading from said casing to said fan-wheel, said throat having its inner termination smaller than its entrance and eccentric to the axis of the fan-wheel, and said entrance being concentric to said axis.

11. In a centrifugal fan or pump, a snailshaped casing, a fan-wheel mounted to rotate therein, and an eye constructed in the form of a throat leading from said casing to said fan-wheel, said throat having its inner termination smaller than its entrance and eccentric to the axis of the fan-wheel, and having its wall on the side whichis nearest the fan-blades extended substantially at right angles to the plane of rotation of the fanwheel, and on the opposite side inclined thereto. I v

12. In a centrifugal fan or pump, a snailshaped casing, a fan-wheel mounted to rotate therein, said fan-wheel being formed of blades of a length materially less than the depth of the casing, whereby there is left a space between the casing and the fan-wheel at the intake end of the latter, and an eye constructed in the form of a threat extending inwardly from said casing across said-space, said throat having its inner termination. smaller than its entrance and eccentric'to the axis of the fan-wheel.

13. In a centrifugal fan or pump, a snailshaped casing, a fan-wheel mounted to rotate therein, said fan-wheel being formed of blades of a length materially less than the depth of the casing, whereby there is left a space between the casing and the fan-wheel at the intake end of the latter, and an, eye constructed in the form of a throat extending inwardly from said casing across said space,

said throat having its inner termination In witness whereofI have hereunto si ed smaller than its entrance and eccentric to the my name in the presence of two subscri ing axis of the fan-wheel, the side of such inner witnesses. termination which is nearest such axis being SAMUEL GLELANI) DAVIDSON, 5 extended into the fan-wheel to a oint be- Witnesses:

end the plane of the intake en s of the JOHN MOORE, h lades. THOMAS DIXON 

